1. Field of the Invention
The present invention relates to a method of molding a flange for a tape reel assembly around which a recording tape is wound and which comprises a reel hub and at least one flange coaxially secured to, and extending radially outwardly from one of opposite axial ends of the reel hub, a tape reel assembly having the flange and a tape cartridge having the tape reel assembly with a recording tape wound therearound.
2. Description of Related Art
In order for a magnetic tape to make both a positioning error signal (PES) which is a value indicating non-uniformity dislocation or a value of a standard deviation of positional dislocation and off-track as small as possible, it has been known from, for example, JP2002-245745A to use a tape reel having a winding shaft which is tapered at an angle of 0.01 to 0.1 degree so as to have a diameter gradually increasing toward an end thereof on a side of an edge of the magnetic tape serving as a reference side for running the magnetic tape. The tape reel further has opposed flanges at an axial distance greater than an upper limit tape width in a range of from 0.204 to 0.224 mm at an innermost position or necks connecting to the winding shaft and a face-to-face axial distance greater than an upper limit tape width in a range of from 0.484 to 0.504 mm at an outermost position or a peripheral position. That is, the flanges of the tape reel are shaped so as to have a face-to-face axial distance greater at an outside periphery than at an inside periphery thereof. However, nothing in the prior art teaches in what shape and how the flanges of the tape reel are manufactured.